As is well known in the relevant arts, glycated hemoglobin (GHb) is formed in a non-enzymatic glycation pathway by hemoglobin's exposure to plasma glucose, over 120-day lifespan of the red blood cell (RBC). A buildup of glycated hemoglobin within the red cell, therefore, reflects the average level of glucose to which the cell has been exposed during its life. It is always expressed as percentage of total hemoglobin.
Measurement of glycated hemoglobin levels may provide more accurate information on blood glucose levels over a long period of time (typically 120 days). In comparison, fasting blood glucose measurements merely indicate blood glucose levels over a much shorter period of time (typically on a daily basis). Estimation of percentage GHb may be valuable, for example, in devising optimum treatment strategies for long term management of diabetes. Various methods for the measurement of glycated hemoglobin are known in the art. Although techniques such as immunoassay, ion-exchange chromatography, electrophoresis, boronate affinity chromatography and high pressure liquid chromatography along with electrospray ionization mass spectrometry are commonly used in the laboratories, these techniques may be time consuming and may require bulky equipments. Other techniques to reduce the size of such equipments exploit the adsorption of GHb onto various materials like Zirconia nanoparticles, Aminophenyl boronic acid agarose beads, Thiophene-3-boronic acid on gold particles. However such materials may be associated with high costs, and designing these instruments may be complex. US patent no. 20100089774A1 discloses a screen printed electrode (SPE) system for detection of glycated hemoglobin and hemoglobin. However this method of detection involves elaborate use of buffers and reagents and uses potentiometric techniques to detect GHb. Addition of precise amount of liquid reagents, needs a lab technician with relevant experience and hence cannot be used by a common unskilled user. The present invention is directed towards the above problem and relates to easy to use disposable sensors for measuring percentage glycated hemoglobin in a blood sample. The inventors propose using a membrane modified with lysing agents, so that it can be used in miniaturized point of care devices for hemoglobin or glycated haemoglobin measurement. This technique eliminates the need for mixing in a separate lysis buffer which is a huge advantage in terms of making a point of care device both more user friendly and more robust. The inventors also propose the methodology for the specific detection of GHb and Hb.